Telephone-transmitter



(No Model.)

T E. BBRL'I NER. TELEPHONE TRANSMITTER.

Patented Apr. 27, 1886.

INVENTOR' I WITNESSES u. PETERS. mmmyw. wmmm o. c

. UNITED STATES-- PATENT OFFICE.

EMILE BERLINER, OF \VASlIlNG-TON,DISTBIGT COLUMBIA.

TELEPHONE-TRANSMITTER.

EJPEUIFIUATION forming part of Letters Patent No. 340,853, dated April2'7, 1886.

Application filed August 17, 1885. Serial No 174,610. (No model.)

To ctZZ whom it may concern.-

Be it known that I, EMILE Bnnmnnn, re siding at Washington, in theDistrict of Golumbia, have invented certain Improvements inTelephone-Transmitters, of which the following is a specification.

My invention relates to telephonic trans mitters of that class in whicha variation of contact produces a variation in the strength of current.Transmitters of this general type have been devised heretofore whichemploy as the current-varyingmedium a number of balls or spheres ofcol'iducting material held between. conducting-plates. These balls orglobules have sometimes been made of 1netal such as lea-d shot-but ballsof carbon have been found most suitable for this purpose. Inpractice,however, it has been found extremely diflicult, in fact almostimpossible, to produce these small. carbon spheres of exactly the samesize, which is aneccssary condition in instruments of this class, sinceotherwise the upper dish or plate does not rest evenly upon the balls,and in consequence more or less of the latter are not included incircuit.

In addition to the initial dilficulty of cutting or to rning the carbonpieces into the form of perfect splilcres of uniform size, there isstill greater di'l'lliculty in preserving this uniformity during theprocess of smoothing and polishing the balls. As will be readilyunderstood, a very slight variation in size will detract from theeiliciency of the instrument.

The present invention is based upon the discovery that the diflicultiesvabove stated may be obviated without sacrifice of the advantagesattending this form of instrument by making the carbon pieces in theform of pen oils or rods 'i. (2., making their shape cylindrical insteadof spherical, it being practically a siinple matter to shape pieces ofcarbon into rods or cyliln'lers of uniform diameter.

The construction of a transmitter inaccordance with the invention is asfollows: One elect-rode is a conducting plate or diaphragm, preferablyof carbon, which is rigidly fixed in position, "Upon this platerests aseries of cylindrical carbon sticks varying in length from the diameterof the plate or diaphragm to the chord of a small are thereof.

' Section A is recessed to receive the metal ring 1', upon which reststhe conducting plate or diaphragm 0, preferably of carbon. Thecasesection 13 is a ring having a flange to fit the recess in A. The twosections are held firmly together by screws or a, thus clamping ring Iand diaphragm G firmly in position. Upon diaphragm (3 there are a seriesof carbon cylinders, l), varying in length, as shown in Fig. 2, fromabout the diameter of the recess in case-section B to the chord of asmall are thereof. These cylinders are free to move, and rest by gravityupon diaphragm C.

E is a plate of conducting material, as carbon, resting by its gravityupon the cylinders 1). One circuit terminal, '1, is connected to plate1*]. Thesecond terminal, e, is connected to diaphragm 0 through ring I.

The sounds for transmission are directed upon diaphragm 0 throughmouthpiece G.

What I claim, and desire to secure by Let tors Patent, is

1. In a telephone-transmitter, the combina' tion of aseries of carbonrods resting loosely between a conducting diaphragm and a looseconductingweight.

2. In a tolephonetransmitter, the combina tion of two plates ofconductil'ig material forming the two electrodes of a circuit and aseries of carbon cylinders located between them.

3. In ittelephoue-transm'itter, the combination of two carbon platesforming the electrodes of a circuit and a series of carbon cyl- I indeislocated between them.

4.. In a batterytransmitier, the combination of a plate and diaphragm ofconducting material forming one electrode of a circuit,

and two or more carbon cylinders forming the second section, a series ofcarbon-cylinders other electrode of saidcircuit. resting upon thediaphragm and a carbon 5. In a battery-transmitter, the combinaplateresting upon the cylinders. 15 tion of a carbon plate or diaphragmrigidly In testimony whereof I have signed myname 5 fixed in position, aseries of carbon cylinders to this specification, in the presence of tworesting upon said plate by their own gravity, subscribing witnesses,this 14th day of August, and aplate of carbon resting upon the said cyl-1885. inders. 6. In atelephone-transmitter, the combina- IO tion of aninclosing-case in two sections, in Witnesses:

one of which islocated a metal ring,and acar- GEO. \VILLIs PIERoE, bondiaphragm firmly held in position by the THOS. D. LOOKWOOD.

EMILE BERLINER.

It is hereby certified that in Letters Patent N 0. 340,853, grantedApril 27, 1886, upon the application of Emile Berliner, of Vvashington,District of Columbia, for an improvement in Telephone-Tranemitters, anerror appears in the printed specification requiring the followingcorrection, viz: In line 99, page 1, the word and should read or; andthat the Letters Patent should be read with this correction therein tomake it conform to the record of the ease in the Patent Office.

Signed, conntersigned, and sealed this 11th day of May, A. D. 1886.

[SEAL] H. L. MULDROW;

Acting Secretary of the Interior. Countersigned M. V. MONTGOMERY,

Commissioner of Patents.

